Molding apparatus



. Oct' 9 1945- UF. E. TRoKLE ET AL 2,386,641

MOLDING APPARATUS Y Filed Jan. 11, 1944 l Patented Oct. 9, 1945 UNITED STATES PATENT OFFICE MOLDING APPARATUS Frank E. Trockle, Everett D'. McClellan, and

William D. Simpson, Akron, Ohio, assignors to A The B." F. Goodrich Company, New York, N. Y.,

a corporation of New York This invention relates to molding apparatus -and morek especially to apparatus for handling molds for molding plastic materials.

. In prior` expedients whereL Vhydraulic presses have been used for performing the molding operor'otherwise heated platens are mounted there- Application January 11, 1944, VSierialNo. 517,790

` s claims. :(01. 1li-1e) Y on for providing heat to the mold members, and

suitable steam connections to the'y heating platens are provided' for circulating a'heating medium thereto.

The cylinder I4 is provided with a U-shaped ation, considerable diiiculty has been experi- 5 gland packing 25forsealing the pressure fluidvr enced inv molding rubber or other rubber-like about the ram I3 and a gland ringy 26, secured materials Vaccurately .to dimensions as aresult by studs 32, holds the packing in place. Fluid of non-uniformity in the placing of molds in the for raising the ram under pressure is connected press, and great strength has been required of to the cylinder by a pipe 21 which handles ilow the operators to manipulate the heavy molds in either direction through a suitable control required. valve (not shown).

The present inventionaimsto overcome the The lower platen is guided in its vertical foregoingand other diiculties. Y movement by bearing shoes 28 formed thereon The principal objects of the invention are lto for engaging the rods I6, I'I, I8, I9 in sliding enprovide accuracyof molding together 'with lfagagement. The lower platen rests on the ram I3 cility 0f handling, to provide uniform positioning but is not xed thereto. -of the molds ln successive molding operations, to Whilethe platens Il, I2 are constructed with provide convenient positioning of themold plates parallel pressing faces, some deection of the for vinspection and cleaning, to provide power platens, due to the great hydraulic pressure emhandling of the upper mold plate, and to provide ployed, isinevitable, and placing of the mold out safety andconvenience of procedure and slmof center ofthe platens may cause some angular plicity of apparatus. or non-parallel presentation of the lower platen These and other objects will appear from folwith respect to the upper one resulting in in- IOWDB description and the aCCOmpanying draW- accuracies of dimensions'of the molded product. ing To provide for accurate placing of the mold OIV the drawing: Y plates in the press so as to duplicate molding con- Fig. `1 is a side elevationpartly broken'away ditions in the forming of successive articles, the and partly in section, of apparatus constructed lower platen I2 is provided with parallel 'guide yin accordance with yandembodying the invenrails 30, 3| for engaging the sides of the lower tion, with the upper guide rails shown inglowmold plate 35, and a stop rail 33 for engaging ered position. and positioning an end thereof. The stop rail .Flg.2 is a Vhorizontal sectional detail view, may have adjusting `screws 34 threaded theretaken on line 4*-4-of Fig. 1, parts rbeing 'broken' through for adjustably positioning the mold. away( Y Y 35Y The lower mold plate 35 is shown as resting on a Fig. 3 is a vertical cross-sectional detail view, table 36 mounted in front of the pressand adapttakenon line 3 3 of Fig. 1. Y y ed to support the mold plate 35 at the same ele- Referring to the drawing, the numeral I0 vation'as thatof the lower platen I2 at its low- Y designates a. hydraulic press having an upper ered position. The rails 3|II, 3| are rounded as fixed platen II and a vertically movable lower 40 at 31, at their front ends to facilitate entry of the platen I2.l The lowerplaten is supported on a mold therebetween and may have overhanging ram I3 vertically movable within a cylinder` I4 ledges 3B for engaging over a'rabbetted margin which forms the base of the press. The cylin- 3S of the mold plate to act as stripping means der has ears II; and strain rods I6, I1, I8, I9 are when the press is opened, if desired, although fixed to the ears and secured by nuts 20 threaded 45 such ledges may usually be omitted. thereon. The upper end of thestrainrods ex- For guiding and positioning the upper mold tend through the upper platen whichris secured plate 40, parallel guide rails 4I, 42 are xed to thereto by, nuts 2|. The rods are reduced in the upper platen, as by screws 43. These rails diameter where they extend through the ears I5 have moldV supporting ledges 44 at the lower sides and through the upper platen and shouldered 5o of their inwardly facing margins for engaging to hold the parts, in properly spaced apart relarabbetted side margins of the upper mold non, Y I plate. Y A stop rail V46 is mounted on the platen The upper and lower platens are hollow to profor positioning the rear margin of the mold plate, vide steam chambers for heating them, or steam and maybeprovided with adjustable stop Screws 41 for adjustably locating the upper mold plate.

' The rails on the upper and lower platens accurately guide the mold plates to the same molding position each time they are inserted in the press so that the molds are properly centered and closed in parallelism and all deflections of the platens and molds are the same at each successive operation so that uniformity of product dimensions is attained.

To provide for inspection and cleaning of the upper mold plate and handling of the plates with a minimum amount of physical exertion on the part of the operator, the upper rails 4I, 42 are made to extend beyond the front of the press and across the table 36, and the rails are made in sections, hinged as at 50 to each other at a position slightly forward of the platen II. The hinged extensions 5I, 52 of the respective rails 4I, 42 are joined by a. cross bar 53 at their forward ends and a handle 54 is provided on the cross bar for handling the extensions in unison. For supporting the extensions and a mold plate 40 supported thereby, over the table 36. a leg 55 is provided on each rail extension and adapted, when resting on the table, to hold the rails in horizontal position as seen in Fig. 1. 'I'he rail extensions with the mold plate 40 may be swung to an inclined position as indicated in dot ,and dash lines by means of the handle 54 or otherwise where the face of the mold plate is exposed to the operator for inspection or cleaning. To

prevent dropping of the mold plate. in the elevated position, a locking pin 80 is provided adapted to pass through an aperture in rail extension 5I in position to block the mold plate against travel along the rail, and upper ledges Sla, 52a are provided on at least the extensions 5I, 52 to extend over the mold plate. Such ledges may also extend throughout the rails 4I, 42, if desired.

For facilitating handling of the upper mold plate and the rail extensions, with a minimum of effort on the part of the operator, a doubleacting iiuid operated cylinder 6I is pivotally mounted, as at 82, between a pair of brackets 63 fixed to the upper platen of the press. Ears 64 are provided on the rail extensions II, l2 and a cross-bar 65 extends between the ears and is secured thereto. The piston rod 66 oi' the cylinder 6I is pivotally connected to the crossbar 65 and connects it to the piston 61 which operates in the cylinder SI. The arrangement is such that when fluid under pressure is supplied to the rod end of the cylinder, the piston is moved to the position shown in dot and dash lines in Fig. 1 and the rail extensions and mold are elevated to the position shown in that figure, and when duid is admitted under pressure to the head of the cylinder and the rod end exhausted, the rail extensions and the mold plate are returned to the horizontal position as shown in full lines in Fig. 1.

For operating the cylinder II, a four-way control valve 10 is mounted at the table 38. Pipes 1I, 12 extend from ports of the valve and are connected by ilexible hose 1I, 14 respectively to the rod end and the head end of the cylinder 6I. Fluid under pressure is delivered to athird port of the valve 10 from a source (not shown) by a pipe 1B. An exhaust pipe 16 is connected to a fourth port of the valve. The arrangement is such that with thevalve handle 11 turned down as shown in full lines in Fig. 1 pipe 1I is opened to exhaust and pipe 12 connected to pipe through the valve and pressure is applied to the head end oi' cylinder BI, while with the valve handle 11 turned to the raised position, as indicated in dot and dash lines in Fig. 1, pipe 12 is opened to exhaust and pipe 1I connected to pipe 15 through the valve, and pressure is applied to the rod end of cylinder 6I to raise the rail extensions.

The operation of the apparatus is as follows:

With the rail extensions 5I, 52 horizontal and the platen I2 lowered as in Fig. 1, the upper mold plate is located in the slide extension as shown and the bottom mold plate is on the table 36. In this position blanks of the plastic materiai are placed on the mold cavities of the lower mold plate and the plate is shoved over the table onto the platen I2 between the guide rails 3u, 3| and against the stop rail. The upper mold plate is pushed back along rails 40, 4| until it strikes the stop 46. The ram I3 is now actuated by applying hydraulic pressure to close the mold. The guide rails are of less depth than the depth of the mold and during vulcanization permit the mold plates to contact the platens. After vulcanization, the cylinder' I4 isl drained to lower platen I2 and separate the mold plates. The lower mold plate 35 is drawn out of the press onto the table and the upper mold plate 40 is drawn from the press onto the rail extensions El, 52. The pin B0 is entered in the opening in rail 5I to block the mold. Then the valve handle 'I1 is moved to raised position, as in Fig. 1 and the cylinder 6I raises the mold plate to the position shown in Fig. 1 without substantial eiIort on the part of the operator. The operatorv may then inspect, clean and reload the mold plates. The valve handle 11 is then turned down, as in Fig. 1, and the rail extensions with the mold plate are lowered to horizontal position. The pin 60 is then removed and the mold plates shoved into the Dress.

The apparatus provides for accurate return of the mold plates to the same `position in the press at each operation. The mold plates are within full sight of the operator for inspection, loading, and cleaning. The operator is relieved from heavy lifting of the mold plates.

Variations may be made without departing from the scope of the invention as it is defined by the following claims.

,We claim:

1. Mold handling mechanism comprising a molding press having platens movable toward and from each other, hinged mold guiding rails having a section secured along a press platen and a section hingedly connected thereto, and means for locking a mold plate within the hinged section of the rails. f

2. Molding handling mechanism comprising a molding press having platens movable toward and from each other, hinged mold guiding rails having a section secured along a press platen, a section hingedly connected thereto, means for locking a mold plate within the hinged section of the rails, and means for bodily moving the hinged section and the mold to a position angular to the secured section.

3. Molding apparatus comprising a molding press having upper and lower platens, the lower oi' which is movable toward and from the upper, a table having a top level with the lowermost poL sition of the lower platen and adjacent thereto, parallel guide rails on the 'lower platen for positioning a mold plate within'the press and guiding it to the table, parallel guide rails on the upper platen for positioning a second mold plate within `the press, extensionI rails hinged to the rails onz the upper platen for positioning a mold plate within the press and guiding it to a position over the table, legs for supporting said extension rails from said table in horizontal position, means for locking the upper mold plate within said extension rails against sliding movement, and means for moving said extension rails angularly about their hinge connection with the mold plate locked therein to increase the accessibility of the face of the mold plate.

4. Molding apparatus comprising a mold, a pair of press platens, means for moving one of the platens toward the other, guide rails on one of the platens arranged to support -said mold, extension guide rails hinged to the tlrst said guide rails in 9, manner for said mold to be moved on said rails across the hinged connection into and out of the space between said platens, and means for moving the extension guide rails about their hinged connection with said mold upon said extension guide rails to an elevated position to increase the accessibility of the face of said mold 5. Molding apparatus comprising a mold having a plurality of separable mold plates, a pair of superimposed press platens, means for moving one of the platens toward and from the other, guide rails on said platens for aligning mold plates therebetween, the rails on the upper platen being arranged to support a mold plate, extension guide rails hinged to the rails of the upper platen in a manner for the mold plate thereon to be moved on said rails across the hinged connection `into and out of the space between said platens, and means for vmoving the extension guide rails about their hinged connection with the mold plate upon said extension guide rails from a generally horizontal position to a position past the vertical to increase the accessibility of the face of said mold plate.

6. Molding apparatus comprising a mold having a plurality of separable mold plates, a molding press having upper and lower platens, the lower of which is movable toward and from the upper,l

a table having a top level with the lowermost position of the lower platen and adjacent thereto, parallel guide rails on the lower platen for positioning a mold plate within the press and guiding it to the table, parallel guide rails on the upper platen for positioning a second mold plate within the press, extension rails hinged to the rails on the upper platen for positioning a mold plate within the press and guiding it across the hinged connection to a position over the table, means supporting said extension rails in a horizontal position above said table, means for locking the vupper mold plate within said extension rails against sliding movement, and means for moving said extension rails angularly about their hinge 

